Implement --omit, --raw_[context_]file=... for mksnapshot tool.

src/flag-definitions.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 636 matching lines @@
 DEFINE_string(testing_serialization_file, "C:\\Windows\\Temp\\serdes",
               "file in which to testing_serialize heap")
 #else
 DEFINE_string(testing_serialization_file, "/tmp/serdes",
               "file in which to serialize heap")
 #endif
 
 // mksnapshot.cc
 DEFINE_string(extra_code, NULL, "A filename with extra code to be included in"
                   " the snapshot (mksnapshot only)")
+DEFINE_string(raw_file, NULL, "A file to write the raw snapshot bytes to.")
+DEFINE_string(raw_context_file, NULL, "A file to write the raw context "
+              "snapshot bytes to.")
+DEFINE_bool(omit, false, "Omit raw snapshot bytes in generated code.")

[Sven Panne, 2014/04/24 06:59:17]

These new flags don't make sense outside of mksnapshot, can we find a way to
restrict them to that? Having them e.g. in d8 is a bit confusing. I know this
problem has been there before, but now we have 4 confusing flags instead of 1.

[vogelheim, 2014/04/24 11:07:59]

I looked at this, thinking it should be really easy to just move those flags to
mksnapshot.cc which contains the main method. Except... the way the current
flags.h/.cc infrastructure is built, it relies on repeatedly including
flag-definitions.h with various defines set to 'extract' different data out of
the macros there. There appears to be no way to modify the data structures used
by flags.h/.cc other than flag-definitions.h; at least I didn't find any.

Honestly, I'm not super fond of this design, but I can't see any fix other than
refactoring the whole flags thing.

[Sven Panne, 2014/04/24 11:12:43]

I suspected that... :-/ OK, then just add "(mksnapshot only)" to the
descriptions.

 
 // code-stubs-hydrogen.cc
 DEFINE_bool(profile_hydrogen_code_stub_compilation, false,
             "Print the time it takes to lazily compile hydrogen code stubs.")
 
 DEFINE_bool(predictable, false, "enable predictable mode")
 DEFINE_neg_implication(predictable, concurrent_recompilation)
 DEFINE_neg_implication(predictable, concurrent_osr)
 DEFINE_neg_implication(predictable, concurrent_sweeping)
 DEFINE_neg_implication(predictable, parallel_sweeping)
@@ skipping 258 matching lines @@
 #undef DEFINE_ALIAS_float
 #undef DEFINE_ALIAS_args
 
 #undef FLAG_MODE_DECLARE
 #undef FLAG_MODE_DEFINE
 #undef FLAG_MODE_DEFINE_DEFAULTS
 #undef FLAG_MODE_META
 #undef FLAG_MODE_DEFINE_IMPLICATIONS
 
 #undef COMMA